This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to provide knowledge about the biological basis of cognitive impairments in MA abusers. The objective is to map abnormalities in brain function in MA abusers, as indexed by regional cerebral hemodynamic changes (activations), measured by fMRI. Activations will be related to performance on neuropsychological tests, to delineate the neurological basis for the behavioral effects of MA (and possible recovery) during 4-5 weeks of abstinence from the drug. We also plan to assess genetic factors implicated in this phenomenon. The information gleaned may help in designing therapies for MA dependence.